Rotary pump and compressor



Aug. 29, 1944. R T R 2,356,915

ROTARY PUMP AND COMPRESSOR 7 Filed Sept. 11, 1940 2 Sheets-Sheet 1 l i m 20 1/2 5- 5 j gamma low Bum/Mg vAug- P. D. BREWSTER 2,356,915

ROTARY PUMP AND COMPRESSOR v Filed Sept. 11, 1940 2 Sheets-Sheet 2 5 a a 7/ 3 7/ a I W A \Q N 27 25 (8 $0 28 2.9 29-" fnyfio aylalfinmrler Patented Aug. 29, 1944 ROTARY PUMP AND COMPRESSOR Percy D. Brewster, Holmdel, N. J., assignor to Casse Brewster, East Orange, N. J.

I Application September 11, 1940, Serial No. 356,249

- 1 Claim.

My invention relates to rotary pumps, motors and fluid engines, and particularly to a type of pump consisting of acylinder in which a rotor revolves, which has a, plurality of cavities in its periphery with rollers in them that are adapted to maintain contact between the rotor cavities and the cylinder bore. 1

In my copending patent application Ser; No. 356,248, flied simultaneously, I described among other things a compound roller for use in this type of pump. The periphery of this roller consists of a plurality of separate concentric rings relation to the others. Some or these rings roll on the cylinder bore, others roll on the rotor slots but none of the rings touches both cylinder bore and the rotor. Bearings, within the compound roller permit the rings to revolve independently with a minimum of friction.

Throughout the specification and claim the term engine is understood to include pumps, motors and engines driven by fluids. The pump illustrated herein has three independent cavities in the periphery of the rotor but it is to be understood that any number of cavities may be used' or the slots may be connected together in the center or the rotor without departing from my invention.

One object of my invention isto-provide a roller that rolls in contact with the entire width of the cylinder bore and does not touch the rotor cavity. Another object is to prevent the ends of the roller from touching the inside of the rotor cavities or the cylinder heads. A further object is to reduce the weightof the rollers and rotor. Another obiect is to provide means at all times for holding the rollers in substantial contact with the cylinder bore. To these and other ends my invention comprises the novel features hereinafter described. Y

My'inventlon consists in constructing a shroud or headeron bothends of the rotor. These headers may be an integral part of the rotor made in one piece or the center portion of the rotor may be cast of a light metal such as an aluminum or magnesium alloy with steel headers at either end integral with the rotor shafts. Slots, equal in numbeiato the cavities in the rotor, are cut in each or the headers spaced equally from one side of each of the said cavities. Shafts, ,either attached toor mounted to turn in the rollers, are

' adapted to roll in the slots in the header or to turn in a bearing-that either rolls or slides in the said header slots.

The rollers are maintained'in substantial consome of which, at least, are free to revolve in tact with the cylinder bore by an extension of the I roller shafts through the rotor headers into grooves turned in both cylinder heads concentric with the cylinder bore. The grooves are sulficiently wide so that while the rollers are in actual contact with the cylinder bore, these extension shafts do not touch the sides or the grooves, but if the rollers leave the cylinder bore a substantial distance, this shaft extension comes into contact with the inside of the groove and prevents the rollers dropping into the cavities.

Fig. 1 in .the drawings is an end elevation of the pump with cylinder head removed; Fig. 2 is half -a top view of the pump and half a section on line AB, Fig. 1; Fig. 3 is an inside view of a cylin-' der head; Fig. 4 is an enlarged section on line CD,

Fig. 1; Fig. 5 is a section through a modified form of roller; Fig. 6 is an end elevation of the roller shownin Fig. 5; Fig. 'l is a section through which the rotor 3 revolves with its periphery just clearing the cylinder bore at one point and journaled in the cylinder heads 4 and 5. Three independent cavities 6, 6, 6 in the periphery of the rotor 3 contain the rollers I, l, l. Headers 8, 8,

preferably of steel with shafts 9, 9 in one piece, are attached onto either side of the rotor 3 to form the complete rotor. When in clockwise operation, the fluid enters the inlet l0 and passes through port ll into the pump and is discharged through port l2 and outlet l3. Three slots is, ll, M are cut in each header an equal distance from one side of each f the cavities. The rollers I may be cast in one piece but, preferably as illustrated in Figs. 1 and 4, they are made of tubing with headers at both ends to which stuo shafts l5, I5 are attached which extend into the slots It. A hearing it, usually a ball bearing is mounted on these stub shafts, the outer race of which is adapted to roll on the sides of the s1ots It. The slots H are preferably sufliciently widein normal operation it does not touch the sides of the groove, but if the rollersleave the bore of the cylinder, the shaft. l1 comes into contact with the groove and keeps the rollers from dropping into the cavities. This groove is not illusthe inside of the rotor header 8, 8 by. the side of the outer race of the bearing l8, Fig. 4, on the roller shaft l5 rolling against the lips II on the outside of the roller slot H. The inner race of this bearing I6 is held against a shoulder on shaft I! by the snap ring lid and positions the roller away from the header when the outer race of the bearing is in contact with the lip l9. Any type of thrust hearing may be substituted for this combined radial and thrust bearing. The cylinder heads and the inside of the headers should be in the same plane so a properly positioned roller just clears both of them.

Under certain conditions, the bearings IS in the rotor header slots may become relatively so large that, when rollers are at the farthest out position in the rotor cavities, the outside of the bearing may touch the bore of recess 20 in the cylinder heads 4 and I, in which the rotor headers turn, and prevent the rollers for a certain distance from touching the cylinder bore 2, 'This is avoided by turning a crescent shaped pocket 2| in this recess 20 that is concentric with the cylinder bore and slightly clears the outside of 1 the bearing IS.

A different arrangement of the rollers and the roller shaft is illustrated in Figs. 5 and 6 in which the roller is arranged to turn on shaft 22 by free to move so this type roller may be also mounted with a thrust bearing in the rotor header slot to keep the roller away from rotor header and cylinder heads.

Figs. '1 and 8' illustrate a roller in which stub shafts 28, 28 are attached to the roller and turn in the cross head 29 which slides in and out in the slot 28a. in the rotor header 8. A. stub shaft may be driven or pressed into a tight .fltting bore in each end of the roller. Tongues in the top and bottom of the cross head 29 at into grooves II, II in the rotor header slots to act as a thrust bearing to guide the roller.

It is to be understood that bearings of any type, plain, needle, roller, etc., may be readily substituted without departing from my invention. The

rollers are so positioned by the bearings in the headers that their periphery does'not quite touch the side of the cavity. This exact clearance which is usually a maximum of a few thousandths of an inch is controlled by the size of the pump, the bearings used, the temperaturu of the fluid in the pump, etc., and is readily determined by tests, but in no case is a consequential part of the fluid lost by leakage.

While the form of the apparatus herein described constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appe ded claim.

A rotary engine comprising a cylinder having a bore, a cylinder head at each end of the cylinder, fluid inlet and discharge ports for said cylinder, a rotor journaled in at least one of said cylinder heads eccentrically relative to said cylinder bore for rotation therein, said rotor comprising a central portion having a plurality of cavities in its periphery and a header secured to each end of said central portion, radial slots in said headers in alignment with said cavities, the sides of said slots being provided with shoulders spaced from theirinner edges, a roller in each of said cavities adapted to contact and roll on said cylinder bore, a shaft extending from each end of each of said rollers into said slots ahd bearing means on each of said shafts engaging the walls of said slots to prevent engagement of said rollers with the walls of said cavities, said bearing means being secured against axial movement on said shafts and engaging said shoulders on the sides of said slots to prevent the ends of said rollers from contacting said headers,

PERCY D. BREWSTER. 

